package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * @Author: fengfeng
 * @Date: 2023/07/06/8:23
 * @Description: 业余爱好者
 * 文件上传和下载
 */
@RestController
@RequestMapping("/common")
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     *
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) throws IOException {

        // 原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        // 使用uuid重新生成文件名，保证文件名唯一
        String fileName = UUID.randomUUID().toString() + suffix;

        // 判断目录是否存在
        File dir = new File(basePath);
        if (!dir.exists()) {
            // 目录不存在，创建
            dir.mkdirs();
        }

        // 将临时文件转存到指定位置
        file.transferTo(new File(basePath + fileName));

        return R.success(fileName);
    }


    /**
     * 文件下载
     *
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        // 输入流，读取文件内容
        FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
        // 输出流，通过输出流将文件写回浏览器，展示图片
        ServletOutputStream outputStream = response.getOutputStream();

        response.setContentType("image/jpeg");

        int length = 0;
        byte[] bytes = new byte[1024];
        while ( (length = fileInputStream.read(bytes)) != -1){
            outputStream.write(bytes, 0, length);
            outputStream.flush();
        }

        // 关闭资源
        outputStream.close();
        fileInputStream.close();

    }
}
